niku khosravi

The prevalence of type 2 diabetes is rapidly increasing in the world. As a result of this disease, long-term insulin resistance develops, as a result of which pancreatic beta cells are destroyed and disappear, as a result insulin is not released. Recently, a protein called lipasin, which is responsible for signaling the liver to beta cells, has been discovered, and previous reports have shown that lipasin/betatrophin increases pancreatic β cell proliferation. Therefore, the aim of this study was to investigate the effect of eight weeks of high intensity interval training (HIIT) and endurance training on lipasin gene expression in rats with type 2 diabetes.

The study was performed on 25 Wistar rats with a mean weight of 160±10 g and age of 8 weeks. After induction of diabetes, the rats were randomly divided into three groups of 6: control and endurance and HIIT. And exercise was performed for eight weeks (5 sessions per week). QRT-PCR technique was used to evaluate changes in hepatic lipasin gene expression.

The present study showed that after eight weeks of endurance training and HIIT, the expression of lipasin gene in the liver of rats in the training group increased significantly compared to the control group (P = 0.037); Also, a significant negative correlation was observed between lipasin gene expression and insulin resistance index in the exercise group compared to the control group (r = -0.605, P = 0.037).

It seems that performing eight weeks of endurance training and HIIT, by increasing the expression of lipasin gene can increase beta cells in diabetic patients and may be an effective non-pharmacological intervention to reduce the symptoms of this disease.

Different protocols of exercise cause different oxidative status. Regular exercises could act like vaccination and up regulate antioxidant systems in body. So 40 male Wistar rats with body weight (154±2 gr) were divided into two groups: 1) trained (n=20) and 2) untrained groups (n=20) at random. Training group participated in eight weeks training program, 5days per week, consisted of treadmill running that began speed was 8 m/min for 10 min and with gradually increase in speed and time reaching the speed of 30 m/min for 1.5 h/day at 8th week.At the end of 8 week each group further divided in to groups where the rats were studied at rest and after exhaustive exercise. For acute exhaustive exercise graded treadmill running was conducted reaching the speed of 35 m/min and was continued until exhaustion, then animals were anesthetized and blood sample were collected for measurements of catalase activity in red blood cell by Abei method and plasma MDA was estimated by spectrophotometry and total antioxidant capacity (TAC) measured by Ferric reducing antioxidant power (FRAP). These results indicated that acute exhaustive exercise increased the MDA level in sedentary but not in trained rat. The catalase activity was elevated significantly in trained group but was unchanged by exhausting exercise and TAC increased in exercise group after exhaustive exercise but decreased in just one session exhaustive group. We conclude that exhaustive exercise induced oxidative stress but endurance training may be useful for preventing acute exhaustive exercise induced oxidative stress by up-regulating antioxidant enzyme activity.

This study aimed at investigating the effect of 8 weeks of endurance training (5 days a week) on NT4/5 protein gene expression in slow twitch (soleus) and fast twitch (EDL) muscles of male Wistar rats. 14 male Wistar rats (age range 50-60 days old, mean weight 160 ± 10 g) were randomly divided into two groups (experimental and control; N=7 for each group). The training protocol consisted of running on a treadmill with 25 m/min for 50 min. for 8 weeks, 5 days per week. After 8 hours of fasting and 24 hours after the last session of endurance training, rats were anesthetized and their soleus and extensor digitorum longus (EDL) muscles were removed under sterile conditions. The mentioned tissues were homogenized and kept in -70̊ C after weighing. RT-PCR method was used to measure the NT4/5 gene expression. Data were analyzed using descriptive statistics and two-way ANOVA (significance level ≤ 0.05). The results showed that 8 weeks of endurance training increased NT4/5 gene expression in soleus and EDL muscles. This increase was greater in EDL while there were no statistically significant differences. It seems that further research is needed to examine the effect of endurance training with more intensity and duration.

Fat oxidation during exercise can be influenced by exercise intensity and duration, training status, diet and physical activity level. However, few studies have investigated the effect of time of day on the rate of fat oxidation during exercise. Thus the present study was designed to investigate the effect of time of day on indexes of fat oxidation in active young women. For this purpose, 14 healthy women (mean±SD age, BF%, weight, BMI and Vo2max: 21.6±1.6 years, 18.3± 4.6 %, 51.2± 3.3 kg, 22±1.7 kg/m2, 40.8±4.2 ml/kg.min) voluntarily participated in this study. The exercise test was performed in two separate sessions in the morning (7:00) and evening (19:00). There was a 7-day interval between the two tests. The protocol was an incremental exercise to exhaustion on a treadmill. The volunteers started exercising at a speed of 58.3 m/min and at a gradient of 1%. Then, the speed increased to 16.7 m/min every three minutes until 125 m/min. At this point, the gradient increased by 2% per three minutes until RER=1 was achieved. VO2 and VCO2 were measured throughout the exercise by an automated gas analysis system. The data were analyzed using independent t test (α=0.05). The findings of the present study showed that no significant difference in maximal fat oxidation between morning and evening exercises (morning: 0.39±0.13 vs. evening: 0.44±0.11, P>0.05). There was no significant difference in FAT Max between morning and evening (P>0.05). However, the mean intensity of maximal fat oxidation was higher in the evening. Finally, it can be concluded that probably time of day (morning and evening) does not have an effect on substrate oxidation during intensive exercise.